annealing frequency when only neck sizing
- Thread starter Pigdog
- Start date
As long as you do not over heat the metal and cause the zinc to drawn out, you will not shorten the life of your cases at all. I anneal ever firing and have 13 firings on them so far (.308 Lapua Winchester Brass).
I anneal each firing as I want consistent metal tension as each firing will harden the material.
It is my belief that annealing should prolong a cases life as it not only softens the metal but it also relieves stress in the metal.
I anneal each firing as I want consistent metal tension as each firing will harden the material.
It is my belief that annealing should prolong a cases life as it not only softens the metal but it also relieves stress in the metal.
I bought an AMP annealer and I anneal every time I reload. With that machine its fast and super consistent. I’ve lost count on the number of times that I have reloaded my 6 Dasher brass and it all looks good and shoots well. It really helps keep a consistent neck tension in my opinion. One of the best things I’ve spent a 1K bill on.
I think this may depend on the amount the brass has been worked to cause work hardening.
If the brass has not been worked much a larger grain size can be obtained after annealing. If the brass has been extensively cold worked the grain size reduction or hardness reduction will not be as great as with brass that has not been cold worked as much.
To achieve this bushing dies or dies that have a honed neck area like Forster F/L dies will help combined with neck turning. The objective is to have necks expand the minimum amount after firing yet permit a slip fit after firing and have adequate neck tension to hold the bullet. Common ordinary dies excessively work necks to provide a "one size fits all" solution for reloading, like hold the bullet regardless of neck wall thickness.
All this involves measurements of chamber, neck walls, and fired cases.
I guess annealing after 3 firings combined with carefully sized brass neck to chamber fits would work.
I don't know about F/L sizing and annealing. It appears that annealing would have little effect on head space and the work hardness of the cartridge head or base would need to be preserved and kept cool during the annealing process, like don't cook the whole case in some oven.
http://che.uri.edu/course/che333/Annealing of 70-30 Brass.pdf
The attachment states that some brass did not change in hardness over time like a straight horizontal red line but other brass did. Could this be brass like Lapua uses?
If the brass has not been worked much a larger grain size can be obtained after annealing. If the brass has been extensively cold worked the grain size reduction or hardness reduction will not be as great as with brass that has not been cold worked as much.
To achieve this bushing dies or dies that have a honed neck area like Forster F/L dies will help combined with neck turning. The objective is to have necks expand the minimum amount after firing yet permit a slip fit after firing and have adequate neck tension to hold the bullet. Common ordinary dies excessively work necks to provide a "one size fits all" solution for reloading, like hold the bullet regardless of neck wall thickness.
All this involves measurements of chamber, neck walls, and fired cases.
I guess annealing after 3 firings combined with carefully sized brass neck to chamber fits would work.
I don't know about F/L sizing and annealing. It appears that annealing would have little effect on head space and the work hardness of the cartridge head or base would need to be preserved and kept cool during the annealing process, like don't cook the whole case in some oven.
http://che.uri.edu/course/che333/Annealing of 70-30 Brass.pdf
The attachment states that some brass did not change in hardness over time like a straight horizontal red line but other brass did. Could this be brass like Lapua uses?
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Seems to me that if the cases actually need (or would benefit from) annealing after 3 reloads, then they gradually changed along the way. So for 3 reloads the cases were all different, while after annealing the fourth firing's case might match the first firing.
Whether that matters or not is another question.
Whether that matters or not is another question.
My guess is if the brass necks were not cold worked very much on each firing an annealing after the 3rd time would restore the brass necks close to their original hardness. This seems to be in agreement with the link. That straight red line on the second diagram in the link sort of shows that all brass is not alike even if is 70-30.
I wonder if you may be misunderstanding the link you provided. "Over time" is not months and years at room temperature. In this instance, it is the time the samples were heated in an oven and in this instance it is measured in minutes at a high temperature.
And it was not different kinds of brass involved in this test. The experiment was measuring the change in hardness for the identical samples which differed only in the amount of cold working they had undergone prior to going into the oven. Remember, we're talking temperatures of 400C. The samples which were significantly work hardened were harder to begin with and they became softer the longer they were in the oven. The samples with less work hardening were softer to begin with and they changed the least during the time they were in the oven. This is not rocket surgery.
And yes, this is very close to the kind of brass Lapua and all other cartridge makers use. Recipes vary to some degree with trace amounts of other metals and not every brand uses the exact same brass, but basically the brass we shooters use is 70/30 cartridge brass and it can all be expected to react like the samples used in the link you provided.
None of this is news to those who have studied metallurgy. The effects mentioned in the link are well understood. These kinds of experiments are the sort of things college students do.
"recrystallization"
No misunderstanding - the graph with that flat red line has time in minutes "Time" and clearly indicated an test end at 45 minutes and 400 degrees C. Time is time and the graph shows that over time (minutes) the hardness did change and I can't understand where "months or years" and "room temperature" could be a read into the discussion as the time was in minutes and temperatures were clearly marked to be 400 degrees C .
The graph shows hardness as RT30. Samples with a RT30 of 75 became softer than those with a RT30 of 55 after only 20 or so minutes but those with an RT30 of 55 maintained a constant hardness . To me this would indicate the less worked brass had less grain growth and maintained hardness. Highly worked brass had greater grain growth over time at 400 C and had more hardness changes.
I would think that the less brass was work hardened the more consistent it would be. The 2 brass samples having a RT30 like close to 74 and 73 at the start had hardness variations that were greater during the test than at the start.
I can clearly see evidences of annealing (not polished off) on Lapua brass as a requirement to reduce effects of work hardening on the brass case introduced during the manufacturing process. Not having measured the hardness of Lapua necks I would guess that Lapua carefully controlled brass grain size and hardness during the annealing process (independent of alloy mix) - this is why "Could this be brass like Lapua uses".
I never did an experiment like this and I never studied metallurgy.
I don't have the equipment or stuff to measure temperatures and am unable to perform Rockwell hardness tests.
I do have a propane torch with a circular flame tip and a cheap alarm clock with a working second hand. Knowing that propane has a flame temp of just under 2000 degrees C (upon complete combustion) how long should I toast my necks that have been carefully prepared to make for minimum work hardening during the load, shoot, load cycle to avoid a financial loss caused by split necks?
Key words - "shooters", "studied metallurgy", "months and years at room temperature", "high temperature", "rocket surgery", "things college students do"
No misunderstanding - the graph with that flat red line has time in minutes "Time" and clearly indicated an test end at 45 minutes and 400 degrees C. Time is time and the graph shows that over time (minutes) the hardness did change and I can't understand where "months or years" and "room temperature" could be a read into the discussion as the time was in minutes and temperatures were clearly marked to be 400 degrees C .
The graph shows hardness as RT30. Samples with a RT30 of 75 became softer than those with a RT30 of 55 after only 20 or so minutes but those with an RT30 of 55 maintained a constant hardness . To me this would indicate the less worked brass had less grain growth and maintained hardness. Highly worked brass had greater grain growth over time at 400 C and had more hardness changes.
I would think that the less brass was work hardened the more consistent it would be. The 2 brass samples having a RT30 like close to 74 and 73 at the start had hardness variations that were greater during the test than at the start.
I can clearly see evidences of annealing (not polished off) on Lapua brass as a requirement to reduce effects of work hardening on the brass case introduced during the manufacturing process. Not having measured the hardness of Lapua necks I would guess that Lapua carefully controlled brass grain size and hardness during the annealing process (independent of alloy mix) - this is why "Could this be brass like Lapua uses".
I never did an experiment like this and I never studied metallurgy.
I don't have the equipment or stuff to measure temperatures and am unable to perform Rockwell hardness tests.
I do have a propane torch with a circular flame tip and a cheap alarm clock with a working second hand. Knowing that propane has a flame temp of just under 2000 degrees C (upon complete combustion) how long should I toast my necks that have been carefully prepared to make for minimum work hardening during the load, shoot, load cycle to avoid a financial loss caused by split necks?
Key words - "shooters", "studied metallurgy", "months and years at room temperature", "high temperature", "rocket surgery", "things college students do"
I anneal after every firing. I'm still using the original cases I bought 2 years ago (Lapua), when I switched to 6mm dasher. I anneal the neck and 1/4" below the shoulder. Cycle time for these cases is about 10+with no problems and good seating tension. I'm using the "GinaErick" induction annealing machine so the annealing is precise and consistent.
I might add that I have a 6.5X47 Lapua and use Lapua brass. I had Forster hone out my Forster F/L dies for .288 neck sizing. I am on cycle 10 with the first batch of 50 and have not been annealed yet. and no split necks. Neck tension is adequate and bullets slip fit into fired cases. Since they cost about $1.20 per piece I am happy to see them as being still useable and able to provide terrific results on tiny targets at tremendous distances.
In a previous life I wrote some computer programs and instructions where I spelied words real good, used by anxious pressured people but never tackled any thing as complex as Web Design.
www.ballisticrecreations.ca --- looks good, hot salt(s)
The operator on u tube used gloves and probably did not have a cold beer or acetone on his work area. The temps were provided as about 570 C and times were about 5 seconds or so per piece. Seems like a good idea for precise temps with common sense safety precautions.
cdc.gov/niosh/ipcsneng/neng0087.html
In a previous life I wrote some computer programs and instructions where I spelied words real good, used by anxious pressured people but never tackled any thing as complex as Web Design.
www.ballisticrecreations.ca --- looks good, hot salt(s)
The operator on u tube used gloves and probably did not have a cold beer or acetone on his work area. The temps were provided as about 570 C and times were about 5 seconds or so per piece. Seems like a good idea for precise temps with common sense safety precautions.
cdc.gov/niosh/ipcsneng/neng0087.html
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Gotta give a big shout out for that machine. I built one myself and I anneal after each firing with consistent results. If you like to build things, I highly recommend taking a look at the thread discussing the build approach.
Here's a link to the thread: A pic of my brass in on page 11.
http://forum.accurateshooter.com/threads/induction-brass-annealer-redux.3908353/page-11
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Correct,college kids that are educated by engineers and professors ,not everyone that reloads has studied metallurgy ...probably why the OP asked the question in the first place .
Keith Glasscock
Gold $$ Contributor
I only anneal if I'm going to full length size. I've never seen any benefit when neck sizing a group of brass with an equal number of firings.
At one point I asked sort of the same question the OP did, "over doing it" -- I asked, "how long should I toast my necks". I don't know very much about metallurgy but know a propane flame of about 2000 C is real hot. Any answers? A minute is about .01 percent of a week and an answer in weeks would be OK.
The salt annealing thingy looks like a single serving crock pot.
The salt annealing thingy looks like a single serving crock pot.
Nice article but the charts are in minutes, not flash annealing for seconds. Cartridge brass will not change grain size annealing for 5 seconds at 900F. It's impossible to burn zinc out of brass at annealing temperatures. I don't shoot comp but my 6BR & 6BRX always shoot small groups annealing about every five shots. Been shooting the same 200 cases for 9 years. Only two case neck cracks. If you are not trying to shoot in competition you don't need extreme neck tension uniformity. I think the big factor in accuracy is the caliber you chose and a good custom barrel like Kreiger, Bartlein, Shilen, Hart. Too many people with crappy barrels trying to make them shoot.
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Shynloco
You can lead a horse to water, but ........
Pigdog,
I'm not fond of only Neck Resizing. Have tried it before and compared the two results, accuracy wise. Where I found the advantage to FL resizing OVER just Neck Sizing is in Concentricity. The runout in FL Resized brass was better than casings that I just Neck Sizing. But as to annealing....I'm an accuracy freak. but no longer compete. And I use strictly Lapua brass because it is the most consistent brass from piece to piece. To that end, like you, I hand anneal all my brass. I use an annealing kit that Hornady used to sell and insert the case holder in an electric screw driver that has low RPM and have learned the timing (different times depending on the size of the casing) to hold the neck junction in the flame of a simply torch that uses coleman latern gas bottles. And considering I only shoot and resize no more than 50 casings (usually around 40) at a time, those fancy Annealers are overkill (in expense) for my low volume of casings I work at any one time. As far as frequency, I anneal every third resizing to keep the brass lively. On my 6br, I'm now on #33 resizing using the same Lapua brass. Works for me.
Alex
I'm not fond of only Neck Resizing. Have tried it before and compared the two results, accuracy wise. Where I found the advantage to FL resizing OVER just Neck Sizing is in Concentricity. The runout in FL Resized brass was better than casings that I just Neck Sizing. But as to annealing....I'm an accuracy freak. but no longer compete. And I use strictly Lapua brass because it is the most consistent brass from piece to piece. To that end, like you, I hand anneal all my brass. I use an annealing kit that Hornady used to sell and insert the case holder in an electric screw driver that has low RPM and have learned the timing (different times depending on the size of the casing) to hold the neck junction in the flame of a simply torch that uses coleman latern gas bottles. And considering I only shoot and resize no more than 50 casings (usually around 40) at a time, those fancy Annealers are overkill (in expense) for my low volume of casings I work at any one time. As far as frequency, I anneal every third resizing to keep the brass lively. On my 6br, I'm now on #33 resizing using the same Lapua brass. Works for me.
Alex
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